1. Field of the Invention
This invention relates to universal joint structures and in particular to improved oil seals for use therein.
2. Description of the Prior Art
In U.S. Pat. No. 2,338,169 of George E. Dunn, a universal joint seal is shown wherein a ball-shaped bearing sleeve is provided around each trunnion with cylindrical rollers between the trunnion surface and the sleeve. An annular ferrule on the trunnion base includes a sleeve portion spaced radially from the trunnion surface and from the outer spherical ball surface at the end of the bearing sleeve. A resilient rubber-like sealing ring is retained within and by the sleeve portion of the ferrule with a compressed portion thereof in sealing contact with the outer spherical surface of the ball.
In U.S. Pat. No. 2,991,634 of Frank R. L. Daley, Jr., a universal joint centering device is disclosed utilizing an annular seal and retainer combination for protecting the interior of the tubular extension and socket means of the device.
Hans-Jaochim Kleinschmidt shown, in U.S. Letters Pat. No. 3,633,383, a universal shaft wherein the seal includes a sealing ring and a scraper ring located adjacent and coaxial to one another, with the scraper ring having a scraping end facing outwardly.
Josef Schultenkamper shows, in U.S. Pat. No. 3,635,535, a universal joint having a seal between the trunnion and bushing.
Harold L. Reinsma, in U.S. Pat. No. 3,841,718, which patent is owned by the assignee hereof, shows a seal for a track linkage wherein a load ring is provided within a crescent-shaped seal having a driving flange, a sealing flange, and a thin flexible hinge section connecting the two flanges. The load ring presses the driving flange into an interference fit with the counterbore walls to cause the driving torque to be transmitted through the seal ring. The arrangement permits the seal ring material to be selected primarily for abrasion, torsional and rotary sealing characteristics without regard to the spring characteristics thereof, while the load ring can be selected primarily for good spring characteristics.